Frost In The Attic Information

Inadequate attic air sealing.

Frost in the attic information. Cold weather climate winter lows of 25c. Frost gets into the attic from air leaks or attic bypasses. When the moisture gets into the attic it condenses on the roof sheathing in the form of frost. The frost itself doesn t do.

When the outside temperature rises again the frost thaws water collects and can leak into. Bypasses are what allow moisture in the attic to begin with and this is what needs repair. I have a 1000sqft attic floor area with two 301 maximum static roof vents. That s about it pretty simple.

When moisture gets into the attic it condenses on the roof sheathing in the form of frost. Check out my post on moldy attics for some. When warm air from inside the house escapes traveling up through the bypasses the moisture condenses on the roof boards and rafters where the frost can form. This post is largely a re blog of my last post on attic frost but that was from 2013 and it s time for a reminder about all of this.

The fix for frost in the attic is sealing attic bypasses these are passageways from the conditioned household space to the attic. While bypasses are certainly the most common cause of frost there are other ways it can happen and these are much more. To start frost accumulates when moisture laden air from the house gets into the attic. Lack of attic air sealing also allows frost to form as warm air penetrating into the attic causes moisture to condense on chilly surfaces.

Full home humidity systems. I noticed that i have frost in my attic in the winter and that one of my 2 roof vents is forming condensation which is dripping onto the insulation. That s about it pretty simple. Houses with full home humidity systems are at risk for attic frost if the home s level of humidity is excessive.